Automatic elevator-regulating brake.



No. 656,838. Patented Aug. 28, I900.

H. GRAVES. AUTOMATIC ELEVATOR REGULATING BRAKE.

(Application filed. July 26, 1899.)

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No. 656,638. Patented Aug. 28, I900.

H. GRAVES.

AUTOMATIC ELEVATOR RE'GULATING BRAKE.

(Application filed July 26, 1899.)

2 Sheets-8haet 2.

(No Model.)

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AUTOMATIC ELEVATOR-REGULATING BRAKE.

SPECIFICATION forming part of Letters Patent No. 656,638, dated August 28, 1900. Application filed July 26, 1899. Serial No. 725,133. (No model.) V

T0 aZZ whom it may concern:

Be it known that I, HIRAM GRAVES, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Automatic Elevator-Regulating Brakes, of which the following is a specification.

My invention relatesto improvements in automatic elevator-regulatin g brakes,and has for its object to provide means for holding the elevator from dropping back after being reversed to go up until sufficient power shall have been communicated to the drum carryingthe suspensory-ropes to raise the load;

My invention is particularly applicable to elevators operated by electric power, in which it often happens that the current is insufficient to carry an increased load. If in such case the elevator is reversed to go up and the main brake released,the elevator will drop back, reversing the motor and burning out the wires. It is the object of my invention to provide an automatic brake which will prevent the elevator from thus running back until sufficient current is generated to raise the load.

In the accompanying drawings, forming part of this specification, Figure 1 is a side elevation of the elevator-actuating mechanism, showing my improved regulating-brake in position as the elevator is descending. Fig. 2 is a plan view of the mechanism shown in Fig. 1. Fig. 3 is a detail of the regulating brake and its actuating mechanism ,taken on liners 00 of Fig. 4:, showing said brake and mechanism in position as the elevator is'goin g down. Fig. 4 is a side elevation taken on the irregular line 00 :0 of Fig. 3, showing theposition of the regulating-brake roller as the elevator is going down. Fig. 5 is a detail of the regulating-brake, taken on line 00 m of Fig. 6, showing the brake and brake mechan-j ism in position as the elevator is going up; and Fig. 6 is a side elevation takenon'the irregular line no at of Fig. 5, showing the parts in position as the elevator is going up. i

In the drawings like letters and figures of reference refer to like parts throughout the several views.

In the drawings, A represents the frame,

upon which is supported the mechanism actuating the elevator. Journaled in suitable bearings 2 on the frame is the main shaft 3, carrying the main driving-wheel 4, which is connected by a belt with a suitable source of power. Also j ournaled in the frame is a shaft 5, uponwhich is loosely mounted a sleeve 6, carrying the spur-gear 7 and the drum 8, around which are Wound the usual suspensory-ropes for raising and lowering the elevator. The power is communicated to. this drum by the driving-wheel 4 through the medium of the pinion 9, intermeshing with the spur-gear 10, mounted upon the intermediate shaft 11, which is journaled in the frame, and the pinion 12, also mounted upon said shaft 11, intermeshing with the spur-gear 7, carried by the drum-sleeve.

Upon the shaft 5, outside of the frame, is mounted the sheave or shifting-wheel13, carrying the usual hand-ropes 14: and the pinion 15, adapted to engage with the teeth 16 upon the outer end of the rack-bar 17, which has sliding support in suitable guides 18 upon the side of the frame. The other or inner end of this rack-bar is provided with rack-teeth 19, adapted to engage with the pinion 20, mounted upon upright shaft 21, which is journaled in suitable bearings 22 in the arms of the bracket 23, attached to the frame, asbest shown in Figs. 3 and 5. Also mounted upon the upright shaft 21 is an eccentric 24, the strap 25 of which is provided with jaws 26, pivotally connected with the outer end of the main brake-lever 27, which is fulcrumed at its in ner end 28 upon the opposite side of the frame. Attached to this lever between itsends is the main brake-shoe 29, adapted to engage with the wheel 30, carried by the main shaft 3,when actuated by the eccentric.

The foregoing mechanism and parts may be. variously changed or modified without affectingimy said invention, the essential feature of which is the regulating-brake now about to be described and suitable actuating lever and its attached brake, mechanism constantly bearing against the cam surface. This lever is fulcrumed upon a bracket 35, suitably secured to the frame, and is formed at its acting end with forked arms 36, adapted to receive the shaft or stem 37 of the regulating-brake, which is supported in said arms and vertically adjustable therein by means of the jam-nuts 38. The brake-shaft 37 has sliding support in a sloping sleeve or guide 39, carried by the bracket 35, and is formed atits lower end with U-shaped arms 40,-provided with longitudinal slots 41, in which is loosely journaled the brake-roller 42, so that said roller is free to move up and down in said slots. The brake-roller 42, which may be made of any suitable friction material, rests normally against the sloping supporting-plate 43, carried by the bracket 35, and is adapted to engage with the wheel 44 when lowered by the lever 34 and its actuating mechanism.

In use the operation of my improved regulating-brake is a follows: WVhen the elevator is descending, the various parts of the mechanism will stand in the position shown in Figs. 1, 2, 3, and 4. From these views it will be seen that the rack-bar 17 is at the end of its travel away from the hand-rope sheave 13, the main brake is out of engagement with the wheel 30, and the cam 32 depresses the stud or roller 33, causing the forked arms 36 to hold the regulating brakeroller 42 in raised position out of engagement with the wheel 44. When the hand-ropes are pulled to stop the elevator, the rack-bar 17 is actuated by the pinion 15 to move toward said pinion half the distance of its travel, thereby, through the medium of the pinion 20 and the eccentric 24, forcing the main brake-shoe 29 into engagement with the wheel 30-and stopping the elevator. The cam 32 is also turned with the upright shaft 21, but not far enough to bring the upwardly-curved cam-surface into contact with the stud 33, so that the regulating-brake 13 remains in raised position. Vthen the hand-ropes are pulled to reverse and raise the elevator, the rack-bar 17 is actuated by the pinion 15 to move toward said pinion the whole distance of its travel, thereby, through the medium of the pinion 20, turning the shaft 21, and with it the eccentric 24 and the cam 32, releasing the brake-shoe 29 and turning the upwardly-inclined cam-face toward and above the stud or roller 33, which follows the cam-face upward, thereby allowing the forked arms 36 to descend and the regulating brake-roller 42 to drop down into engagement with the wheel 44, as shown in Figs. 5 and 6. If new the power should be insuflicient to support the load, the elevator would be held from dropping by the brake-roller 42, which would be wedged tightly between the wheel 44 and the supporting-plate 43, thus effectually preventing the wheel 44 and the main shaft 3 from turning backward. When the power is sufficient to turn the main shaft 3 and wheel 44 forward again, as shown by the arrow in Fig. 6, the brake-roller 42, being free to move vertically in the slots 41, will simply be lifted in the slots, so that it will offer no obstacle to the forward turning of the wheel 44 and shaft 3. When the elevatoris stopped in its upward ascent, the main brake will be set and the cam 32 will be turned by the mechanism described to raise the brake-roller 42 out of engagement with the wheel 44, and when the hand-rope is pulled to start the elevator upward again the main brake will be released and the brake roller 42 dropped down again into the position shown in Figs. 5 and 6.

In Fig. 1 the cam 32 is shown so shaped-that when turned by the mechanism described in stopping the elevator in its upward ascent the brake-roller will not be raised out of engagement with the wheel 44.

While I prefer to use the mechanism above described for actuating my improved regulating-brake, my invention is not limited to the exact mechanism described nor to the particular form of power applied or method of applying it, for the brake can equally well be actuated by electricity or other sources of power, the essence of my invention being the provision of a brake which, however actuated, will operate to stop the elevator from dropping back under a too-heavy load when reversed to go up.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an elevator of the class described, the combination, with the main shaft, of a wheel operatively connected therewith,a brake-supporting plate adjacent to said wheel, a plunger slidably supported upon said plate and carrying at its lower end a movably-mounted brake-roller resting against said plate, and mechanism connected with the hand-ropes for actuating said plunger to thrust said roller into, and raise it out of, contact with said wheel.

2. In an elevator of the class described, the combination, with the main shaft, of a wheel operatively connected therewith, a brakeplate adjacent to said wheel, a plunger carrying at its lower end a brake-roller movable in the plane of rotation of said wheel and workingupon said plate, and mechanism for actuating said plunger to lower said roller into, and raise it out of, contact with said wheel.

3. In an elevator of the class described, the combination, with the main shaft, of a wheel operatively connected therewith, a brakeplate adjacent to said wheel, a plunger carryin g at its lower end a brake-roller movable in the plane of rotation of said wheel an d working against said plate, and mechanism for raising and lowering said plunger consisting of a le- Ver connected at one end with said plunger, a cam engaging the other end of said lever and mechanism connected with the handropes for turning said cam.

4. In an elevator of the class described, the combination, with the main shaft, of a wheel operatively connected therewith, a brakeplate adjacent to said wheel, a plunger provided with U-shaped arms, a brake-roller journaled in longitudinal slots in said arms, and working upon said plate, and mechanism for lowering said roller into, and raising it out of, engagement with said wheel.

5. In an elevator of the class described, the combination, with the main shaft, of a wheel carried thereby, an automatic brake consisting of a back plate, a sleeve or guide carried bysaid back plate,-a brake-stem slidabl y su pported in said guide and provided with slotted U-shaped arms, a brake-roller loosely journaled in the slots in said arms and bearing against said back plate, and mechanism for lowering said roller into engagement with said wheel when the elevator is actuated to ascend, and raising it out of such engagement when the elevator is actuated to descend.

6. In an elevator of the class described, the combination, with the main shaft of a wheel carried thereby, an automatic brake, consisting of an inclined back plate adjacent to said wheel and formed with a sleeve or guide, a brake-stem slidahly supported in said guide and provided with longitudinally-slotted U shaped arms and a brake-roller loosely journaled in said slots and bearing against said back plate, and means for lowering and raising said roller into and out of engagement with said wheel consisting of a brake-supporting lever, a cam engaging with the end of said lever and mechanism connected with the hand-ropes for turning said cam as the elevator is stopped or started.

7. In an elevator of the class described, the combination, with the main shaft and handropes, of a wheel carried by said shaft, a brake device consisting of an inclined back plate provided with a sleeve orguide, a brakeesaess a stem slidablysupported in said guide and provided with longitudinally-slotted U-shaped arms, and a brake-roller loosely journaled in said slots and resting against said back plate, and means to actuate said roller to move into and out of engagement with said wheel consisting of a rotatable shaft, mechanism connected with said hand-ropes to rotate said shaft as the elevator is stopped or started, a cam mounted upon said shaft, and a lever engaging at one end with said brake-stem and at the other end with said cam.

8. In an elevator of the class described, the combination with the main shaft, and main elevator-brake, of a wheel operatively connected with said main shaft, a stationary plate adjacent to said wheel, a brake-roller interposed between said plate and wheel and adapted to work upon the surface of said plate, a lever connected with said roller for thrusting it into, or raising it out of, engagement with said Wheel, and means substantially as described for operating said lever and main brake in unison.

9. In an elevator of the class described, the combination with the main shaft,and main elevator-brake, of a wheel operatively connected with said main shaft, a stationary plate adjacent to said wheel, a brake-rollerinterposed between said wheel and plate and having yielding engagement with said wheel as the main shaft is rotated to raise the elevator and wedging engagement therewith when-the rotation of said shaft is reversed, and means substantially as described for lowering said roller into, or raising it out of, engagement with said wheel and operating said main brake, in unison.

In testimony whereof I affix my signature in presence of two witnesses.

I-IIRAM GRAVES.

WVitnesses:

ARTHUR P. LOTHROP, J OHN J. LEIGHTON. 

